Method and apparatus for reproducing sound



5 Sheets-Sheet l S. M. HULL Nov. 5, 19,29.

METHOD AND APPARATUS FOR REPRODUCING SOUND Filed Aug. 17, 1927 rlllullnl l-llll Nov. 5, 1929. s, M, HULL METHOD AND APPARATUS FOR REPRODUGING soUND Filed A11g- 17. 1927 3 Sheets-Sheet 2 Nov. 5, 1929'I s. M. HULL y METHOD AND APEARATUS FOR REPRODUCING SOUND Filed Aug. 17, 1927 3 Sheets-Sheet 3 Patented Nov. 5, 1929 l i -n uNiTEo STATES PATENT oi-FlcE BIDEY I. HULL, l' WESTERN SPRINGS, ILLINOIS METHOD AND APPARATUS FOB BEPBDUCING SOUND Application med August 17, 1927. Serial llo. 213,687.

The sound producing apparatus of my fashion, the modulations of the current being invention is inclusive of a plurality of light exactly similar` in their amplitude, fr uency, varying records, means for furnishing'light and other electric characteristics to t e vato said records the records and light cooperriations of the ima e on the record disc,

5 ating to furnish differing musical scale tones, which in turn, is retrabl the photographic a5 means individual to each record for indi counterpart of t e tone rom which it was A vidually controlling the light furnished produced. The hotoelectrie cell current, thereto, and sound producing means subject preferably ampli edsuiciently by vacuum to and o erable by the varied light. In the tubes in a manner well known tb the radio 1 preferre embodiment of the invention I emart, actuates a loud speaker orl other sound oo ploy a plurality of individually controlled producing mechanism, also well known. As lamps, each record having a lamp individual many photographic ima es are necessary as thereto and subject to light therefrom and are the tones desired, w ile the light correadapted to vary such light in conformity spending to each tone image is turned on or 15 with the record, there being means individual olf in accordance with the keys depressed on a5 to each lamp for bringing it into and out of the console, and the arrangement of the stops cooperative relation with the record indiat the time of depression. It is obvious that vidual thereto. The embodiment of the inany reasonable combination of keys, stops, vention herein disclosed I have cho-sen to call lights and tone-images may be provided or o an. orchestral or an which is designed to employed. 'mi

function as a mo ern organ in churches, the- The invention will be more fully explained aters, schools and other auditoria, and by reain connection with the accompanying drawson of its design and construction is readily ings which illustrate the p eferred equipadaptable to use in smaller spaces, such as ment. In the drawings, Fig. is a front eleresidences. Its operation as performed by vation of the record photo raphing appa- 'l5 the operator may be identical with that of the ratus, the enclosing casing ing shown in modern pipe organ. The tone-producing section; Fig. 2 is a rear e evation of the possibilities of my organ are far greater than apparatus shown in Fi l, the casing also bethose of a modern instrument, since by suiting shown in section; ig. 3 is a side view of 3 able choice of stops and other apparatus conthe ap aratus shown in Figs. 1 and 2, thes0 trolled thereby, the music produced may be casing eing shown in section; Fig., 4 is an identical with that of any pipe organ desired, illustration, p largely diagrammatic, of a or as an alternative, all the tones produced musical instrument equipped in accordance may be those of orchestral instruments rangwith the invention; Fig. 5 is a View illustraty ing from those of the double bass viol, ing the preferred mechanical arrangement of 'sa through the cello, viola, oboe, horns, etc., to a number of recording members, elements the highest or the shrillest tones of the violin pertaining to and complemental to one of harmonics or flute. these members being illustrated;y and Fig. 6

The entire tone-producing mechanism' of is a face view of vone of the recordin mem-V the orchestral organ may .be summed up berswith a circular row of lamps in ront of 90 briefly by stating that the tone produced v1s the record ,bearing lface thereof. developed b c allowing light to shine upon l In Figures 1v to 6 of the accompanying y and prefere ly through a suitable image, drawings,I-haveshownindiagrammatic form, ,t

' preferably photographic', of the tone desired the apparatusl and arrangement thereof necon asuitable recording member which is pref- `essary for the execution of the invention 96 erably a revolving plate or disc. v The light fully described in the foregoing specification. emerging from the image is preferably In the preparation of these drawings, no focused upon a photoelectric cell, which alattempt has been'made to illustrate the melows an electric current to be transmitted chanical details necessary for the insta-lla- 0 through it in an oscillating or modulated tion ofthe apparatus since it is obvious that in 10G the mechanical construction of the apparatus a variety of methods may be employed to accomplish the same end. The illustrations are diagrammatic only and fully demonstrate the principles involved in all the essential features, both as to apparatus and its coordination.

Figure 1 shows the front elevation of the apparatus necessary for photographing the single or complex tones desired. A is a lightproof box within which are located a disc B mounted on its axle C and held firmly thereon by the locknut D; a light relay E, mounted by a sliding clamp F on a support G; and a screw adjustment H actuated by the turning of a small hand wheel above the box, for varying the position of the light relay before the disc vertically between the axley and the periphery of the disc B.

Figure 2 represents the rearl elevation of the photographic apparatus shown in Figure 1, wherein letters A to H designate the same details as in Fig. 1; L is a speciied constant speedmotor for rotating the disc B at a number of prescribed constant speeds of rotation, by the worm and spiral gears, J and I respectively. The various speeds of rotation desired may be secured byv replacing I and J with other gears of appropriate size and number of teeth, or by substituting therefor any other suitable train of gears necessary. The motor L is mounted on a sliding base M, whose position is varied by turning the screw adjustment N in order to allow replacement of various sizes of worm and spiral gears.

In Figure 3 is shown the side elevation of the photogra hic apparatus illustrated in Figures 1 an 2. Herein, the letters A to M designate identical parts of the apparatus shown in Figures 1 and 2. Here, owever, the light relay L is shown in a side view with its lamp Q. O is amicrophone and Pis a suitable source of potential in series in an electrical circuit with the winding in the light relay. R is a suitable source of potential and S is a variable rheostat both of which are placedin series with the lamp Q and are employed for supplying a regulated electrical current to the filament of said lamp.

The light relay L may be of any type but the preferred form is fully describedl in an article by Franz Aigner in the Jahrbuch der drahtlosen Telegraphie und Telephonie for 1923, pages lOl-120.

Let it be assumed that the tone images are to be photographically placed on a series of discs B of glass. Each disc may be three feet in diameter, and a quarter of an inch thick, free from optical defects and perfectly plane over its area on both sides, which should be exactly parallel. Each disc is coated with a photosensitive coating, similar to a glass photographic camera plate, projection lantern slide, etc. Each glass disc is mounted on the horizontal, revolving support C inside the light proof box A. The shaft support may be projected through the side of the box and driven by the suitable constant-speed motor L', either electrically o'r spring actuated, and so designed that, within a certain range, the disc may be driven at any constant speed desired. Before the disc and mounted on the vertical sliding support G is the light relay E of the type customarily employed in the photographing of sound where the sound vibrations, by means of the microphone O, are transformed into electrical oscillations, which, in turn, either control the intensity of a transmitted beam of light or, by the use of another type of light relay, control the path of a beam of light, both processes servmg to expose a photosensitive surface to variations in intensit or path of light, in a manner corresponding to the characteristics of the original sound vibrations. The preferred type of relay is a device by which the intensity of a light aixed thereto is varied in proportion to the variations of an electric current passed through a .solenoid winding within the light relay. A sto arrangement is provided whereby the lig t shining through the light relay, with the glass disc being driven at constant speed, w1ll be allowed to shine upon the surface of the revolving disc for exactlyy one revolution of said disc. The relay is so supported on the sliding mounting G within the box, that, without opening said box, the relay can be locked in a number of varying positions before the disc. The relay is mounted on the slidin support in a manner customarily employed in dphotographing sound vibrations and provi ed with the necessary apparatus for the proper exposure of the sensltlzed surface.

The microphone O is placed in series with the light relay and the suitable s ource of' current P and the entire sound photography apparatus is ready for' use.

Suppose that it is desired to image the tones of a musical instrument such as the cello. The musician sits with his instrument properly placed in frontof the microphone, the light relay is adjusted in the box, so that it illuminates a spot on ..the disc just 'outside the central mounting (say, three inches from the center of revolution) and the motor is started. As yet the spot before the relay has not been exposed to light since the stop shutting oii' the light has been kept closed. When the motor has attained constant speed, the musician now plays the lowest tone to be recorded, by bowing his instrument. At the proper moment, with the tone being sounded true and clear, the stop is opened and the light relay exposes an endless annular record concentric with the disc, six inches in diameter, in exact response to the tone vibrations recorded by the microphone. After the disc has rotated through exactly one revolution, the stop is closed, with the result that an annular endless sound record is produced upon the disc. After this first record is produced, the relay is moved half an inch upward and with the next higher tone being played upon the cello, anothpr endless annular record concentric with and immediately surrounding the first is produced in a similar manner. Successive endless annular records of increasing diameter are similarly made until finally the recording member or disc B is completely covered with records of varying diameter and corresponding to the differing tones that were produced by the instrument being recorded. In short, these concentric endless annular records correspond, respectively, to the tones in a chromatic scale so that they may be selected for reproduction in proper sequence to produce music. After the complete exposure to all the desired tones, the disc is taken to a dark room where it is removed from its light proof box and developed in the usual or preferred manner. The result will be a series of concentric endless records, one for each half inch, upon the surface-of the disc, and each endless annular record will vary in light and shade, being transparent or opaque, the succession of these light and dark areas on the circular record varying in frequency of occurrence and intensity of transparency, in a manner corresponding exactly to the modulations of the tones correspondingly produced on the cello. Allowing a radial width of one half inch for each record, one octave of twelve tones can be imaged on the disc per six inches of radius, consequently with a diameter of forty-two inches, allowing six inches for mounting on `the shaft, three octaves would be photographed. On many instruments, two octaves rangewould be sufficient, so that thirty inches diameter of disc would be adequate.

The endless annular tone record or lowest pitch is nearest the-center of the recording member. Each tone record of high- `er pitch surrounds the tone records of lower pitch, the tone records increasing in diameter or size in correspondence with the increase in the pitch of the tones, in correspondence with the chromatic scale. It is thus seen that as the tone images progress towardthecircumferenceofthedisc,the linear or peripheral speeds thereof increase, with the rotation of the recording member B at uniform speed, in almost the same ratio as the vibration rates of the tones recorded. If desired, the radial spacing of the tone records upon the surface of the disc may be so calculated with respect to both the speed of rotation and frequency of the tone to be photographed, that an exactly integral number of sound vibrations will be photographed in one revolution of the' disc.

In the photographing of a tone by the above method, the speed of revolution and the constancy of that speed are preferably made essential factors. In general, the linear or peripheral Speed of the recording areas of surface which pass before the light relay should only be the minimum speed at which the light vibrations, as they are projected onto the disc, will not superimpose upon each other. In other Words, the critical speed is that speed at which, when the image is developed on the plate, the recorded vibrations of the highest frequency will be drawn out laterally, or, in this case, circumferentially, to produce a vibration record.

The man ner of taking photographic records of tones produced by any selected musical instrument or instruments or sounds produced by other sound producing instrumentalities may be in accordance with the process hitherto described. The invention, however, is not to be limited to any peculiar form of record nor to any peculiar process of making such records, excepting that such records are produced by the` action of sound or are copies, replicas.or' reroductions thereof.

In Figure 4 we leave the photographic apparatusand illustrate in turn the complete diagrammatic set-up for the reproduction of the tones photographed with the apparatus shown in Figs. 1 to 3, in response to the depression of keys at a keyboard. a designates a plurality of keys connected in series, through a plurality of choke coils d, with a plurality of lamps e wherein each keyis electrically connected through its individual choke coil to its individual lamp. A, common source of potential f and a common variable choke df are connected in series with the key-lamp circuits in such a way that the potential source f supplies electrical energy to any or all of the lamps in response to the depression of the keys corresponding to said lamps. The variable choke coil dis connected mechanically in any suitable manner to a foot pedal at the console in order that the operator, b depressing the pedal, may cause the core o lthe said choke coil to be withdrawn therefrom and thus increase the amperage and, in turn, the brilliancy of the light produced by the lamps e. Obviously, the effect of operation of the choke coil d is to vary, as desired, the intensity of the illumination to vary the musical tones. The adjustable choke coil, which is common to the records, is used where the lamps are supplied With alternating current; obviously other instrumentalities could be employed. The choke coils d are adjusted during installation of the apparatus to provide suitable equalization in the intensities of the lights produced byjvthe said lamps. If the source of potential f is alternating in character, d and d may be choke coils, but if direct current is used, d and d" would necessarily be direct current resistances of suitable construction. b and o are electrical contacts for closing the electrical circuits between the keys and the lamps in order that the lam s may light in response to depression of t e keys. y

B is the disc carrying upon its surface the more or less transparent, endless circular photographs of the desired tones. It is mounted upon an axle g to which it is firmly secured by the two collars o o. A single lamp e is placed directly in front of each corresponding tone photograph and when a particular key is depressed, the li ht from the corresponding lamp is projecte through the photograph of the corresponding tone and is reflected by the cone-shaped mirror h with a conver ent lens at its apex, upon the anode of the plbiotoelectric cell z'. If desired, individual lenses may be used in place of the cone mirror. When in operation, of course, the disc B is being rotated by a suitable motor and drive (not shown) at the identical speed at which it was rotating when the photographs which it carries were produced.

In response to the variation of light A thrown upon it by the lamps e, the photoelectric cell z' transmits the current produced by the spurce of potential k in an oscillating manner, identical with the original electrical oscillations produced by the microphone O in Fig. 3. The vacuum tube j with its A battery' n and B battery o amplifies the oscillating current transmitted by the photoelectric cell z' and in turn, is connected with the input leads of the amplifying unit l. The amplifier Z amplifies the current from the vacuum tube j suflicientl to operate the loud speaker m, which re ro uces the combination of tones desired. If desired, the vacuum tube j may be omitted and the photoelectric cell 'i connected directly through the battery k to the input terminals of the amplifier' Z. The manner of electrically connecting the photoelectric cell, vacuum tube and loud speaker, and the specifications therefor are matters of common knowledge and need not be described here. It is important to note, however, that both the amplifier l and the loud speaker m should beso constructed that they will best amplify and reproduce sounds over a limited range of frelquency corresponding to the tones whose photographs are used in the reproduction of said tones through the said amplifier and loud speaker.

Figure 5 illustrates the distribution of discs carrying tone photographs of tones within one limited range of fre uency and wherein all photographs were ta en at one constant speed. In the final assembly of the complete instrument, a plurality of such shafts, with their appropriate discs, are mounted parallel to one another and are so .used in a geared together that one constant speed motor will produce rotation of all the discs at the respective speeds at which the photographs were produced on each disc. t represents a support for the lamps e and, naturally, a set of lamps, as shown in Fivure 4, would be provided in front of eac disc, while behind each disc would be located the cone-shaped mirror and photoelectric cell with its circuit as shown in detail in Figure 4. In the final assembly the source of otential lc would supply current to a plura ity of photoelectric cells and the circuits from said cells would be grouped in parallel and connected to an amplifier and loud speaker designed particularly for the limited range of frequency within which would fall the frequencies of all tones used in connection with said amplifier and loud speaker.

Figure 6 illustratesthe method of distributing and supporting the lamps e lin front of the discs B in order that the Alight from each lamp may strike the side of the cone-shaped mirror h at the same angle and will thus have an equal share of effect in the activation of the photoelectric cell z'. e represents the backs of the individual lights which are arranged on a circular support t 'impinge justl within the mouth of the cone on. the slanting side thereof.

As illustrated herein, the various lamps e are individually controlled by the keys a whereby the lamps may be caused to glow to project light upon the records or may be caused to cease to glow according to the position of the keys. Obviously, however, other means may be employed for' preventing or permitting light-to pass from the lamps to the records. The claims mention sound producing ap aratus, this expression being road sense to be inclusive of a sound receiver w ich may be located in the neighbqrhood of' he recording member and lamps or which may be widely separated'l therefrom and operated by broadcasting.

If an organ with fifty sto sis desired, fifty discs B will be prepared rom the original tone photographs by printing from the originals, in exactly the manner of printing a icture from a photographic negative. These iscs and the lamps e are now divided into groups, according to the speed at which the photographs were taken and each group of discs is mounted on one or more horizontal eighteen inches to two feet apart along the,

' anaem-A shafts, and the various shafts are gearedtogether so that, when driven by a constant either small filament lamps or they may be small glim lamps of the type of the Well known neon ionization lamp. The lamps should be very responsive to the application or disconnection of current from them, si'nce =the entire success of theA operation may depend upon the immediate response of the light tothe depression of the keys at the console. The ionization lamp is more suited to this purpose than any'other type, since it is instantaneous in its response and moreover, has a very low current consumption.

If we presume that in the production of the original tone images, one note may have been layed louder than others on either the same mstrument, or in comparison with the proper intensity of the tones of other instruments, this difficulty is easily overcome. It is only necessary to introduce the proper amount of resistance into the lamp-key circuit, to reduce the intensity of thelillumination produc-ed by the lamp for this tone, and the difficulty is solved. In this Way, it might `be said that the organ is voiced.

The use of alternating current in the keylamp circuits for flashing the lamps before the tone images is advantageous also, since by its use, simple choke coil impedances could be employed for varying the current strengths of the various circuits, and conseuently, the intensity of illumination prouced by the lamps. In this way, either a I change in the number of turns in the coil or the insertion or withdrawal of the core (even in slight amounts) would constitute an easy method of light intensity control, in instances where variations in the tone intensity of any tone, or combination of tones, by

manual or stop, is desired. The lamps e arev in a circular support on one side of the axis of the recording member, the lamps pertainingv to immediately adjacent rows being on opposite sides of such circular row. It will be apparent that the endless records of individual musical scale tones and the light furnishing means are relatively movable in a direction and to an extent enabling the light to move along the records and throughout their lengths to enable the production of k` continuous tones during the relative movement of the light and records.

What I claim is:

1. In a sound producing apparatus, the combination with a recording member which has a plurality of differing and differently located substantially endless light varying records of individual musical scale tones; of means for furnishing light to all of said records to be varied thereby; means individual to mh more for individually controlling the .light furnished thereto; and

, sound producing means subject to and operable b the varied-light, the records and the light urnishing means being relatively movable in a directionl and to an extent enablin the light to move along the records an throughout their lengths Ato enable the production of continuous tones during the relative movement of the light and records.

2. In a ..sound producmg apparatus, the combination with a recording member which has a plurality of differing and dilferently located substantially endless light transmitting light varying records of individual musical scale tones; of means for furnishing l light to all of said records to be varied therev by; means individual to each record .for individually controlling the light furnished thereto; and sound producin means subject 'to and o erable by the varie light, the records an the lightfurnishing means being` i" relatively movable in a direction and to an'A extent enabling the light to move along the records and throughout their lengths to enable the production of continuous tones vduring the relative movement of the light and records.

3. In a sound producing apparatus, the combination with a recording member which has a (plurality of differing and differently locate substantially endless light varying records of individual musical scale tones;

of means for furnishin li ht toall of said records to be varied t eri means individual to each record for individually controlling the light furnished thereto; an electrically operated sound producing receiver;

an operating electrical circuit for said rei.

ceiver and inclusive of a source of current; and means sensitive to light in controlling relation to said circuit and sub'ect to the light that is varied by the recor s, the reco rds and the li ht furnishing means being relatively mova lein a direction and to an extent enabling the light to move along the records and throughout their lengths to enable the production of continuous tones during the relative movement of the light and records.

4. In a sound producing apparatus, the combination with a recording member which has a lurality of'diifering and differently locate substantially endless light transmitting light varying records of individual musical'scale tones; of means for furnishing light to all of vsaid records to be varied thereby; means individual to each record for individually controlling the light furnished thereto; an electrically operated sound producin receiver; an operating electrical circuit or said receiver and inclusive of a source of current; and means sensitive to light in controlling relation to said circuit and subject to the light that is varied by the records, the records and the light furnishing means being relatively movable in a direction and to an extent enabling the light to move along the records and throu hout their lengths to enable the production of continuous tones during the relative movement of the light and records.

5. n a sound producing apparatus, the combination with a plurality of substantially endless light varying records; of means for furnishing light to said records, the records cooperatin with the light in furnishing diil'ering in ividual musical scale tones; means individual to each record for individually controlling the light furnished thereto; and sound producin means subject to and o erable by the varie light, the records an the light furnishing means being relatively movable in a direction and to an extent enabling the light to move along the records and throughout their lengths to enable the production of continuous tones during the relative movement of the light and records.

6. The sound producing ap aratus of claim 1 wherein the light furnishing means is inclusive of a plurality of individually controlled lamps each record having a lamp individual thereto.

7. The sound producing ap aratus of claim 2 wherein the light furnisliing means is inclusive of a plurality of individually controlled lamps each record having a' lamp individual thereto..

8. The sound "roducin ap aratus of claim 3 wherein tie light urn1s ing means is inclusive of a plurality of individually controlled lamps each record having a lamp individual thereto.

9. The sound producing ap aratus of claim 4 wherein the light furnis ing means is inclusive of a plurality of individually controlled lamps each record having a lamp individual thereto. y

lfkThe sound producing apparatus of claim 5 wherein the light furnishingmeans is inclusive of a plurality of individually controlled lampsv each record having a lamp individual thereto.

11. In a sound producing apparatus, the combination with a recording member which has a plurality of differing and differently located light varyinr musical scale tone records; of means for fiirnishing light to all of said records to be varied thereby; means individual to each record for individually controlling the light furnished thereto; and sound producing means subject to and operable by the varied light, wherein the records are in the form of substantially concentric endless rings of difering diameters and the records and light furnishing means are relatively rotatable on an axis that substantially contains the common center of said records to enablethe light to move along the records.

12. In a sound producing a paratus, the combination with a record memger which has a plurality of differing and dierently located light varying musical scale tone records; of means for furnishing light to all of said rec-- ords to be varied thereby; means individual to each record for individually controlling the light furnished thereto; and sound producing means subject to and o erable by the varied light, wherein the lig t furnishing means is inclusive of a pluralty of individually controlled lamps, each record having a lamp individual thereto and subject to light therefrom, and wherein the records are in the form of substantially concentric endless rings'of differing diameters and the records and the lamps are relatively rotatable on an axis that substantially contains the common center of said records to enable the li ht from the lamps to move along the records, t e lamps being circularly disposed on one side of the' aforesaid axis.

13. In a sound producing apparatus, the combination with a recording member which has a lurality of diiering and differently locatedp light varying musical scale tone records; of means for furnishing light to all of said records to be varied thereby; means individual to each record for individually controlling the light furnished thereto; and sound producing means subject to and operableb the varied light, wherein the light furnis ing means is inclusive of a plurality of individually controlled lamps, each record having a lamp 'individual thereto and subj ect to light therefrom, and wherein the records are in the form of substantially endless rings of differing diameters and the records and the lamps are relatively rotatable on an axis that substantially contains the common center of said records to enable the light from the lamps to move along the records, the lamps being arranged in a circular row on one side of the aforesaid axis, the lamps pertaining to immediately adjacent records being in opposite sides of the circular row of such lamps.

14. The sound producing a paratusl of claim 1 wherein means, in ad ition to the light controlling means, are provided for varying the intensity of the tones.

15. The sound producing apparatus of claim 2 wherein means, in additionpto the light controlling means, are provided for varying the intensity of the tones.

16. The sound producing apparatus of claim 3 wherein means, in addition to they light controlling means, are provided for varying the intensity of the tones.

17. The sound producing apparatus of claim 4 wherein means, in addition to the light controlling means, are provided for light controlling means, are provided forvarying the intensity of the tones.

22. The sound producing apparatus of claim l wherein means, common to the records and in addition to the light controlling means, are provided for varying the intensity of the tones.

23. The sound producing apparatus of claim 2 wherein means, common tothe records and in addition to the light controlling means,

are providedfor varying the intensity of the' tones. v

24. The sound producing apparatus of claim 3 wherein means, common to the records v and in addition to the light controlling means,

are provided for varying the intensityy of the tones. i

25. The sound producing apparatus of claim 4 wherein means, common to the records and in addition to the lig'ht controlling means, are provided for varying the intensity of the tones.

26. The sound producing apparatus of claim 5 wherein means, common to the records and in addition to the light controlling means, are provided for varying the intensity ofthe tones. y

27. The sound producing apparatus of claim 11 wherein means, common to the records and in addition to the light controlling means, are provided for varying the inten.- sity of the tones.

28. The sound producing apparatus of claim 12 wherein means, common to the records and in addition to the light controlling means, are provided for varying the intensity ofthe tones.

29. The sound producing apparatus of claim 13 wherein means, common to the records and in addition to the light controlling means, are provided for varyingthe intensity of the tones.

30. In a sound producing apparatus, the combination with a recording member which has a plurality of differing and diierently located substantially endless light varying records of individual musical scale tones; of means for furnishing light to all of said records to be varied thereby; means individual to each record for individually controlling the light furnished thereto; sound producing means subject to and operable by the varied light, the records and the light furnishing means being relatively movable in a direction and to an extent enabling the light to move along the records and throughout their lengths to enable the production of continuous tones during the relative movement of thelight and records; and means, in addition to the light controlling means, to vary the intensity of the tones, said tone varying means being in controlling relation to the light furnished to the records.

.31. In a sound producing apparatus, the combination with a recording member'which has a plurality of differing and differently located substantially endless light transmitting light varying records'of individual musical scale tones; of means for furnishing Light to all-of said records to be variedtherey. aiiduauy controlling the iight furnished thereto sound producing'means subject to and operable by the varied light, the records and the light furnishing means being relatively movable in a direction and to an eX-I tent enabling the light to move along the records and throughout their 'lengths to enable the production of continuous tones during the relative movement of the light and records; and means, in addition to the light controlling means, to vary the intensity of the' tones, said tone varying means being in mea-ns individual .to each record for in-y controlling relation to the light furnished. I

to the records.

32. In a sound producing apparatus, the combination with a recording member which vhas a (plurality of differing and diilerently locate substantially endless light varying recordsof individual musical scale tones; ot' means for furnishing light to all of said rec* ords to'be varied thereby; means individual to each record for indivi dually controlling the light furnished thereto; an electrically oper ated sound producing receiver; an operating electrical circuit for said receiver and inclusive of a source of current; means sensitive to light in controlling relation to said circuit and subject to the light that is varied by the records, the records and the light furnishing means being` relativel movable in a direction and to an extent ena lingthe light to move along the records and throughout their lengths to enable theproduction of continuous tones during the relative movement of ,the light and records, and means, in addition to the light controlling means, to vary the intensit of the tones, said tone varying means ing in controlling relation to the lightfurnished to the records.

33. In a sound producing apparatus, the combination with a recording member which has a plurality of differing and differently locatedsubstantially endless light transmitting light varying records of individual musical scale tones ,of means for furnishing light to all of said records to be varied thereby;

means individual to each .record for individually controllin the l`llight furnished thereto; an electrica ly operated sound producin receiver; an operating electrical circuit or said receiver and.l Inclusive of a source of current; means sensitive to light.

in controlling relation to said circuit and subject to the light that is varied by the records, the records and the light furnishing means being relatively movable in a direction and to an extent enabling the light to move along the records and throughout their lengths to enable the production of continuous tones during the relative movement of the light and records; and means, in addition to the light controlling means, to vary the intensit of the tones, said ,tone varying means eing in controlling relation Vto the light furnished to the records.

34. In a sound producing apparatus, the combination with a plurality of substantially endless light varying records; of means for furnishing light to said records, the records cooperating with the light to furnish differing individual musical scale tones; means individual to each record for individually controlling the light furnished thereto; sound producing means subject to and operable by the varied light, the records and the light furnishing means being relatively movable in a direction and to an extent enabling the light to move along the records and throughout their lengths to enable the production of continuous tones during the relative movement of the light and records; and means, in addition to the light controlling means, to vary the intensity of the tones, said tone varying means being in controlling relation to the light furnished to the records.

35. In a sound producing apparatus, the combination with a recording member which has a plurality of differing and differently located light varying musical scale tone records of means 'for furnishin light to all of said records to be varied t ereby; means individual to each record for individually controlling the light furnished thereto; sound producin means subject to and operable by the varie light, wherein the records are in the form of substantially concentric endless ringsl of differing diameters and the records and light furnishing means are relatively rotatable on an axis that substantially contains` the common center of said records to enable the light to move along the records; and means, in addition to the li ht controllin means, to vary the intensity o? the tones, sai tone varying means being in controlling relation to the llght furnished to the records.

36. In a sound producing apparatus, the combination with a recording member which has a plurality of dilering and differently located light varying musical scale tone records; of means for furnishing light to all of said records to be varied thereby; means means is inc ally controlled lamps, each record having a' individuall to each record for individually controlling the light furnished thereto `sound producin means subject to and operable by the varie light, wherein the light urnishing usive of a plurality of individulamp individual thereto and subject to light therefrom, and wherein the records are in the form of substantially concentric endless rings of ditfering'diameters and the records and the lam s are relatively rotatable on an axis that su stantially contains the common l center of said records to'enable the' light from the lamps to move along the records, the lamps being circularly dis osed on one side ofthe axis; and means, in a dition to the light controlling means, to vary the intensity of the tones, said tone var ing means being in controllin relation to tli'e light furnished to the recor s.

37. In a sound producing apparatus, the combination with a recording member which has a plurality of diering and differently located light varying musical scale tone records; of means for furnishing light to all of said records to be varied thereby; means individual to each record for individually controlling the light furnished thereto sound producing means subject to and operable by the varied light, wherein the light furnishin means is inclusive of a plurality of indiviually controlled lamps, each record having a lam individual thereto and sub'ect to light there rom, and wherein the recor s are in the form of substantially endless rings of differing diameters and the records and the lamps are relatively rotatable on an axis that substantially contains the common center of said records to enable the light from'the lamps to move along the records, the lamps bein arranged in a circular row on one side o the aforesaid axis, the 'lamps pertaining to immediately adjacent records being in opposite sides of the circular row of such lamps; and means, in addition to the light controllin means, to vary the intensity of the tones, sai tone va ing means being in controllin relation tot e light furnished to the recor s.

SIDNEY M. HULL. 

